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Full-Text Articles in Physical Sciences and Mathematics

Strong Electron-Boson Coupling In The Iron-Based Superconductor Bafe1.9pt0.1as2 Revealed By Infrared Spectroscopy, Mumtaz M. Qazilbash Dec 2018

Strong Electron-Boson Coupling In The Iron-Based Superconductor Bafe1.9pt0.1as2 Revealed By Infrared Spectroscopy, Mumtaz M. Qazilbash

Arts & Sciences Articles

No abstract provided.


Constraints On Cosmic Strings Using Data From The First Advanced Ligo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, Eugeniy E. Mikhailov, H. Rew, M. Zhang May 2018

Constraints On Cosmic Strings Using Data From The First Advanced Ligo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, Eugeniy E. Mikhailov, H. Rew, M. Zhang

Arts & Sciences Articles

Cosmic strings are topological defects which can be formed in grand unified theory scale phase transitions in the early universe. They are also predicted to form in the context of string theory. The main mechanism for a network of Nambu-Goto cosmic strings to lose energy is through the production of loops and the subsequent emission of gravitational waves, thus offering an experimental signature for the existence of cosmic strings. Here we report on the analysis conducted to specifically search for gravitational-wave bursts from cosmic string loops in the data of Advanced LIGO 2015-2016 observing run (O1). No evidence of such ...


Highly Repeatable Nanoscale Phase Coexistence In Vanadium Dioxide Films, Mumtaz M. Qazilbash Feb 2018

Highly Repeatable Nanoscale Phase Coexistence In Vanadium Dioxide Films, Mumtaz M. Qazilbash

Arts & Sciences Articles

No abstract provided.


Q(Weak): First Direct Measurement Of The Proton's Weak Charge, D. Androic, David S. Armstrong, A. Asaturyan, Todd Averett, J. Balewski, K. Bartlett, J. Beaufait, R. S. Beminiwattha, J. Benesch, F. Benmokhtar, J. Birchall, R. D. Carlini, G. D. Cates, J. C. Cornejo, S. Covrig, M. M. Dalton, C. A. Davis, Wouter Deconinck, J. Diefenbach, J. F. Dowd, J. M. Finn, V. M. Gray, K. Grimm, J. R. Hoskins, J. Leckey, J. H. Lee, J. A. Magee, S. Yang Jan 2017

Q(Weak): First Direct Measurement Of The Proton's Weak Charge, D. Androic, David S. Armstrong, A. Asaturyan, Todd Averett, J. Balewski, K. Bartlett, J. Beaufait, R. S. Beminiwattha, J. Benesch, F. Benmokhtar, J. Birchall, R. D. Carlini, G. D. Cates, J. C. Cornejo, S. Covrig, M. M. Dalton, C. A. Davis, Wouter Deconinck, J. Diefenbach, J. F. Dowd, J. M. Finn, V. M. Gray, K. Grimm, J. R. Hoskins, J. Leckey, J. H. Lee, J. A. Magee, S. Yang

Arts & Sciences Articles

The Q(weak) experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q(2) = 0.025 ( GeV/c)(2). The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be ...


Ultrafast Multidimensional Laplace Nmr Using A Single-Sided Magnet, Jared N. King, Vanessa J. Lee, Susanna Ahola, Ville-Veikko Telkki, Tyler Meldrum Mar 2016

Ultrafast Multidimensional Laplace Nmr Using A Single-Sided Magnet, Jared N. King, Vanessa J. Lee, Susanna Ahola, Ville-Veikko Telkki, Tyler Meldrum

Arts & Sciences Articles

Laplace NMR (LNMR) consists of relaxation and diffusion measurements providing detailed information about molecular motion and interaction. Here we demonstrate that ultrafast single- and multidimensional LNMR experiments, based on spatial encoding, are viable with low-field, single-sided magnets with an inhomogeneous magnetic field. This approach shortens the experiment time by one to two orders of magnitude relative to traditional experiments, and increases the sensitivity per unit time by a factor of three. The reduction of time required to collect multidimensional data opens significant prospects for mobile chemical analysis using NMR. Particularly tantalizing is future use of hyperpolarization to increase sensitivity by ...


A Sonic Net Excludes Birds From An Airfield: Implications For Reducing Bird Strike And Crop Losses, John P. Swaddle, Dana L. Moseley, Mark H. Hinders, Elizabeth P. Smith Mar 2016

A Sonic Net Excludes Birds From An Airfield: Implications For Reducing Bird Strike And Crop Losses, John P. Swaddle, Dana L. Moseley, Mark H. Hinders, Elizabeth P. Smith

Arts & Sciences Articles

Collisions between birds and aircraft cause billions of dollars of damages annually to civil, commercial, and military aviation. Yet technology to reduce bird strike is not generally effective, especially over longer time periods. Previous information from our lab indicated that filling an area with acoustic noise, which masks important communication channels for birds, can displace European Starlings (Sturnus vulgaris) from food sources. Here we deployed a spatially controlled noise (termed a “sonic net”), designed to overlap with the frequency range of bird vocalizations, at an airfield. By conducting point counts, we monitored the presence of birds for four weeks before ...


Factoring A Quadratic Operator As A Product Of Two Positive Contractions, Chi-Kwong Li, Ming-Cheng Tsai Jan 2016

Factoring A Quadratic Operator As A Product Of Two Positive Contractions, Chi-Kwong Li, Ming-Cheng Tsai

Arts & Sciences Articles

Let T be a quadratic operator on a complex Hilbert space H. We show that T can be written as a product of two positive contractions if and only if T is of the form aI circle plus bI circle plus [GRAPHICS] on H-1 circle plus H-2 circle plus (H-3 circle plus H-3) for some a, b is an element of [0, 1] and strictly positive operator P with parallel to P parallel to < = vertical bar root a - root b vertical bar root(1 - a) (1 - b). Also, we give a necessary condition for a bounded linear operator T with operator matrix [GRAPHICS] on H circle plus K that can be written as a product of two positive contractions.


Climate Change As Migration Driver From Rural And Urban Mexico, Raphael J. Nawrotzki, Lori M. Hunter, Daniel M. Runfola, Fernando Riosmena Nov 2015

Climate Change As Migration Driver From Rural And Urban Mexico, Raphael J. Nawrotzki, Lori M. Hunter, Daniel M. Runfola, Fernando Riosmena

Arts & Sciences Articles

No abstract provided.


Dual-Sensor Fluorescent Probes Of Surfactant-Induced Unfolding Of Human Serum Albumin, Christopher J. Abelt Mar 2015

Dual-Sensor Fluorescent Probes Of Surfactant-Induced Unfolding Of Human Serum Albumin, Christopher J. Abelt

Arts & Sciences Articles

Two extrinsic fluorescent probes, 3-(dimethylamino)-8,9,10,11-tetrahydro-7H-cyclohepta[a]naphthalen-7-one (1) and 7-(dimethylamino)-2,3-dihydrophenanthren-4(1H)-one (2), are used to probe the unfolding of human serum albumin by sodium dodecyl sulfate (SDS). These probes respond separately to the polarity and H-bond-donating ability of their surroundings. Competitive binding experiments show that fluorophore 1 binds to site I (domain IIA) and 2 binds to site II (domain IIIA). The local acidity of 1 in site I is out of the sensing range of 1, whereas the local acidity of 2 in site II is calculated to be nearly ...


Undocumented Migration In Response To Climate Change, Raphael J. Nawrotzki, Fernando Riosmena, Lori M. Hunter, Daniel M. Runfola Jan 2015

Undocumented Migration In Response To Climate Change, Raphael J. Nawrotzki, Fernando Riosmena, Lori M. Hunter, Daniel M. Runfola

Arts & Sciences Articles

No abstract provided.


Urbanization And The Carbon Cycle: Contributions From Social Science, Peter J. Marcotullio, Sara Hughes, Andrea Sarzynski, Stephanie Pincetl, Landy Sanchez Peña, Patricia Romero-Lankao, Daniel M. Runfola, Karen C. Seto Aug 2014

Urbanization And The Carbon Cycle: Contributions From Social Science, Peter J. Marcotullio, Sara Hughes, Andrea Sarzynski, Stephanie Pincetl, Landy Sanchez Peña, Patricia Romero-Lankao, Daniel M. Runfola, Karen C. Seto

Arts & Sciences Articles

This paper outlines the contributions of social science to the study of interactions between urbanization patterns and processes and the carbon cycle, and identifies gaps in knowledge and priority areas for future social scientific research contributions. While previously studied as a unidimensional process, we conceptualize urbanization as a multidimensional, social and biophysical process driven by continuous changes across space and time in various subsystems including biophysical, built environment, and socio‐institutional (e.g., economic, political, demographic, behavioral, and sociological). We review research trends and findings focused on the socio‐institutional subsystem of the urbanization process, and particularly the dynamics, relationships ...


What Makes Green Cities Unique? Examining The Economic And Political Characteristics Of Grey And Green Cities, Daniel M. Runfola, Sara Hughes Jan 2014

What Makes Green Cities Unique? Examining The Economic And Political Characteristics Of Grey And Green Cities, Daniel M. Runfola, Sara Hughes

Arts & Sciences Articles

In the United States, urbanization processes have resulted in a large variety—or “continuum”—of urban landscapes. One entry point for understanding the variety of landscape characteristics associated with different forms of urbanization is through a characterization of vegetative (green) land covers. Green land covers—i.e., lawns, parks, forests—have been shown to have a variety of both positive and negative impacts on human and environmental outcomes—ranging from increasing property values, to mitigating urban heat islands, to increasing water use for outdoor watering purposes. While considerable research has examined the variation of vegetation distribution within cities and related ...


Creating Spatially-Explicit Lawn Maps Without Classifying Remotely-Sensed Imagery: The Case Of Suburban Boston, Massachusetts, Usa, Nicholas M. Giner, Colin Polsky, Robert G. Pontius Jr, Daniel M. Runfola, Samuel J. Ratick Jan 2014

Creating Spatially-Explicit Lawn Maps Without Classifying Remotely-Sensed Imagery: The Case Of Suburban Boston, Massachusetts, Usa, Nicholas M. Giner, Colin Polsky, Robert G. Pontius Jr, Daniel M. Runfola, Samuel J. Ratick

Arts & Sciences Articles

Residential lawns are a dominant and growing feature of US residential landscapes, and the resource-intensive management of this landscape feature presents major potential risks to both humans and the environment. In recent years, scientists and policymakers have been increasingly calling for large-extent measures of lawns and other similar landscape features. Unfortunately, the production of such datasets using traditional, remotely sensed measurement approaches can be prohibitively expensive and time consuming. This study uses two statistical prediction methods to extrapolate the quantity and spatial distribution of residential lawns from a sample of mapped lawns in a large study area in suburban Boston ...


A Critical Knowledge Pathway To Low-Carbon, Sustainable Futures: Integrated Understanding Of Urbanization, Urban Areas And Carbon, Patricia Romero-Lankao, Kevin Gurney, Karen Seto, Daniel M. Runfola Jan 2014

A Critical Knowledge Pathway To Low-Carbon, Sustainable Futures: Integrated Understanding Of Urbanization, Urban Areas And Carbon, Patricia Romero-Lankao, Kevin Gurney, Karen Seto, Daniel M. Runfola

Arts & Sciences Articles

Independent lines of research on urbanization, urban areas, and carbon have advanced our understanding of some of the processes through which energy and land uses affect carbon. This synthesis integrates some of these diverse viewpoints as a first step toward a coproduced, integrated framework for understanding urbanization, urban areas, and their relationships to carbon. It suggests the need for approaches that complement and combine the plethora of existing insights into interdisciplinary explorations of how different urbanization processes, and socio‐ecological and technological components of urban areas, affect the spatial and temporal patterns of carbon emissions, differentially over time and within ...


North America, Patricia Romero-Lankao, Joel B. Smith, Daniel M. Runfola, Debra J. Davidson Jan 2014

North America, Patricia Romero-Lankao, Joel B. Smith, Daniel M. Runfola, Debra J. Davidson

Arts & Sciences Articles

No abstract provided.


Improved Upper Limits On The Stochastic Gravitational-Wave Background From 2009-2010 Ligo And Virgo Data, J. Aasi, B. P. Abbott, R. Abbott, E. E. Mikhailov, G. Romanov Jan 2014

Improved Upper Limits On The Stochastic Gravitational-Wave Background From 2009-2010 Ligo And Virgo Data, J. Aasi, B. P. Abbott, R. Abbott, E. E. Mikhailov, G. Romanov

Arts & Sciences Articles

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Omega(GW)(f) = Omega(alpha)(f ...


Local Solvent Acidities In Beta-Cyclodextrin Complexes With Prodan Derivatives, Christopher J. Abelt Mar 2013

Local Solvent Acidities In Beta-Cyclodextrin Complexes With Prodan Derivatives, Christopher J. Abelt

Arts & Sciences Articles

The local solvent acidities (SA scale) of six 6-carbonyl-2-aminonaphthalene derivatives as beta-cyclodextrin complexes in water are determined through fluorescence quenching. The local polarities (E-T(N) scale) are determined through the shift of the emission center-of-mass. The apparent SA values reflect the solvent structure surrounding the guest's carbonyl group, whereas the apparent E-T(N) values reveal the net polarity of the entire guest molecule. Comparison of these values affords greater insight into the structures of the host-guest complexes. Derivatives 1 and 5 show unusually large acidities, indicative of highly exposed carbonyl groups. The remaining compounds give emission intensities pointing to ...


Spatial Interferences Of Photodetachment Near A Repulsive Center, B. C. Yang, M. L. Du, John B. Delos Jan 2013

Spatial Interferences Of Photodetachment Near A Repulsive Center, B. C. Yang, M. L. Du, John B. Delos

Arts & Sciences Articles

We study the detached-electron flux distributions from the photodetachment of electrons from a negative ion near a repulsive center. Using a semiclassical approach, we calculate the electron flux on spherical detectors with various radii. The classically allowed angular range of the interference patterns on the spherical screen increases as the detached-electron energy is increased. In the classically allowed range, we find that there are always two trajectories going from the negative ion to the observation point on the screen, inducing quantum interference patterns. We have also extended the formulas into the tunneling region. The interference patterns also reflect the quantum ...


Eigenvalue Pairing In The Response Matrix For A Class Of Network Models With Circular Symmetry, Miriam Farber, Charles R. Johnson, Wei Zhen Jan 2013

Eigenvalue Pairing In The Response Matrix For A Class Of Network Models With Circular Symmetry, Miriam Farber, Charles R. Johnson, Wei Zhen

Arts & Sciences Articles

We consider the response matrices in certain weighted networks that display a circular symmetry. It had been observed empirically that these exhibit several paired (multiplicity two) eigenvalues. Here, this pairing is explained analytically for a version of the model more general than the original. The exact number of necessarily paired eigenvalues is given in terms of the structure of the model, and the special structure of the eigenvectors is also described. Examples are provided.


Thermal Tuning Of Mid-Infrared Plasmonic Antenna Arrays Using A Phase Change Material, Mikhail A. Kats, Romain Blanchard, Patrice Genevet, Zheng Yang, Mumtaz M. Qazilbash, D. N. Basov, Shriram Ramanathan, Federico Capasso Jan 2013

Thermal Tuning Of Mid-Infrared Plasmonic Antenna Arrays Using A Phase Change Material, Mikhail A. Kats, Romain Blanchard, Patrice Genevet, Zheng Yang, Mumtaz M. Qazilbash, D. N. Basov, Shriram Ramanathan, Federico Capasso

Arts & Sciences Articles

No abstract provided.


Model Sensitivity In Holographic Superconductors And Their Deconstructed Cousins, Joshua X. Erlich, Zhen Wang Jan 2013

Model Sensitivity In Holographic Superconductors And Their Deconstructed Cousins, Joshua X. Erlich, Zhen Wang

Arts & Sciences Articles

Holographic models of superconductors successfully reproduce certain experimental features of high-temperature superconductors, such as a large gap-to-Tc ratio compared to that of conventional superconductors. By deconstructing the extra dimension of these holographic models, similar phenomenology is described by a class of models defined in the natural dimension of the superconducting system. We analyze the sensitivity of certain observables in holographic and deconstructed holographic superconductors to details of the extra-dimensional spacetime. Our results support the notion that certain quantitative successes of simple models of this type are accidental. However, we also find a certain universal relationship between superconducting observables.


Atom Economical, One-Pot, Three-Reaction Cascade To Novel Tricyclic 2,4-Dihydro-1h-Benzo[F]Isochromenes, Robert J. Hinkle, Shane E. Lewis Jan 2013

Atom Economical, One-Pot, Three-Reaction Cascade To Novel Tricyclic 2,4-Dihydro-1h-Benzo[F]Isochromenes, Robert J. Hinkle, Shane E. Lewis

Arts & Sciences Articles

A three-step domino reaction between 1-aryl-3-hexyne-2,6-diol derivatives and aldehydes is used to construct tricyclic 1,4-dihydro-2H-benzo[f]isochromenes. The cascade is initiated by BF3·OEt2 and involves alkynyl-Prins cyclization, Friedel–Crafts alkenylation, and dehydration/aromatization to create a new, central aromatic ring and eliminate 2 equiv. of water. Electron-donating substituents on the aryl ring of the 1-aryl-3-hexyne-2,6-diols significantly increase overall yields as do electron-rich aldehyde reaction partners. For 2,4-disubstituted 2H-benzo[f]isochromene products, diastereoselectivities in the alkynyl-Prins reaction are ∼1.4 : 1 in favor of the cis-diastereomer. The stereochemistry of ...


Excited State Calculations In Solids By Auxiliary-Field Quantum Monte Carlo, Fengjie Ma, Shiwei Zhang, Henry Krakauer Jan 2013

Excited State Calculations In Solids By Auxiliary-Field Quantum Monte Carlo, Fengjie Ma, Shiwei Zhang, Henry Krakauer

Arts & Sciences Articles

We present an approach for ab initio many-body calculations of excited states in solids. Using auxiliary-field quantum Monte Carlo, we introduce an orthogonalization constraint with virtual orbitals to prevent collapse of the stochastic Slater determinants in the imaginary-time propagation. Trial wave functions from density-functional calculations are used for the constraints. Detailed band structures can be calculated. Results for standard semiconductors are in good agreement with experiments; comparisons are also made with GW calculations and the connections and differences are discussed. For the challenging ZnO wurtzite structure, we obtain a fundamental band gap of 3.26(16) eV, consistent with experiments.


Ultra-Thin Perfect Absorber Employing A Tunable Phase Change Material, Mikhail A. Kats, Deepika Sharma, Jiao Lin, Patrice Genevet, Romain Blanchard, Zheng Yang, M. Mumtaz Qazilbash Nov 2012

Ultra-Thin Perfect Absorber Employing A Tunable Phase Change Material, Mikhail A. Kats, Deepika Sharma, Jiao Lin, Patrice Genevet, Romain Blanchard, Zheng Yang, M. Mumtaz Qazilbash

Arts & Sciences Articles

No abstract provided.


Synthesis And Properties Of Two Prodan-Based Fluorescent Models Of Cholesterol, Christopher J. Abelt Jun 2012

Synthesis And Properties Of Two Prodan-Based Fluorescent Models Of Cholesterol, Christopher J. Abelt

Arts & Sciences Articles

The syntheses and photophysical properties of 1-(5-methylhexyl)-2,3,7,8-tetrahydro-1H-naphtho[2,1-e]indo1-9(6H)-one (7a) and 1-(5-methylhexyl)-23,8,9-terrahydro-1H-naphrho[2,1-e]indol-6(7H)-one (7b) are reported. They are prepared in eight steps from the corresponding bromonaphthylamines. These fluorescent compounds have PRODAN-like cores, and they are structurally similar to cholesterol. Compound 7a is the first reported PRODAN derivative where both the amino and carbonyl groups are constrained to be coplanar with the naphthalene core. Comparing the photophysical behavior of these compounds with related compounds indicates that locking the amino group in a five-membered ring enhances ...


Insulator-To-Metal Transition And Correlated Metallic State Of V 2 O 3 Investigated By Optical Spectroscopy, M. K. Stewart, D. Brownstead, S. Wang, K. G. West, J. G. Ramirez, M. Mumtaz Qazilbash, N. B. Perkins, I. K. Schuller, D. N. Basov May 2012

Insulator-To-Metal Transition And Correlated Metallic State Of V 2 O 3 Investigated By Optical Spectroscopy, M. K. Stewart, D. Brownstead, S. Wang, K. G. West, J. G. Ramirez, M. Mumtaz Qazilbash, N. B. Perkins, I. K. Schuller, D. N. Basov

Arts & Sciences Articles

No abstract provided.


Does Prodan Possess An O-Tict Excited State? Synthesis And Properties Of Two Constrained Derivatives, Christopher J. Abelt Apr 2010

Does Prodan Possess An O-Tict Excited State? Synthesis And Properties Of Two Constrained Derivatives, Christopher J. Abelt

Arts & Sciences Articles

The synthesis and photophysical properties of 7-(dimethylamino)-3,4-dihydrophenanthren-1(2H)-one (7) and 3-(dimethylamino)-8,9,10,11-tetrahydro-7H-cyclohepta[a]naphthalen-7-one (8) are reported. These compounds possess a cycloalkanone substructure that controls the extent of twisting of the carbonyl group. The six-membered ring in 7 forces the carbonyl group to be coplanar with the naphthalene ring, whereas the seven-membered ring in 8 induces a significant twist. Both have the substructure of PRODAN (6-propionyl-2-(dimethylamino)naphthalene, 1). Comparing the photophysical behavior of these compounds with that of PRODAN and 2,2-dimethyl-1-(4-methyl-1,2,3,4-tetrahydrobenzo[f]quinolin-8-yl)propan-1-one (3) indicates ...


Urban Dereliction As Environmental Injustice, Daniel M. Runfola, Katherine B. Hankins Jan 2010

Urban Dereliction As Environmental Injustice, Daniel M. Runfola, Katherine B. Hankins

Arts & Sciences Articles

American cities are increasingly suffering from property abandonment and dereliction. In this paper, we identify urban dereliction as an important and underexamined phenomenon in American cities, and one that warrants attention under the conceptual umbrella of environmental justice. An environmental justice approach that emphasizes both distributional and procedural justice provides an important lens through which to examine abandonment and dereliction. We provide an empirical example of dereliction in Atlanta neighborhoods and report preliminary findings from a study of the distribution of urban neglect and the presence (or absence) of resident activism in both high- and low-dereliction areas. Our study indicates ...


Preparation Of 5-Bromo-2-Naphthol: The Use Of A Sulfonic Acid As A Protecting And Activating Group, Christopher J. Abelt Jun 2009

Preparation Of 5-Bromo-2-Naphthol: The Use Of A Sulfonic Acid As A Protecting And Activating Group, Christopher J. Abelt

Arts & Sciences Articles

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2-naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid.


Photoluminescence Of 1-D Copper(I) Cyanide Chains: A Theoretical Description, Craig A. Bayse, Timothy P. Brewster, Robert D. Pike Nov 2008

Photoluminescence Of 1-D Copper(I) Cyanide Chains: A Theoretical Description, Craig A. Bayse, Timothy P. Brewster, Robert D. Pike

Arts & Sciences Articles

Solid copper(I) cyanide occurs as extended one-dimensional chains with interesting photophysical properties. To explain the observed luminescence spectroscopy of CuCN, we report a series of computational studies using short bare and potassium-capped [Cun(CN)n+1] − (n = 1, 2, 3, 4, 5, and 7) chains as CuCN models. On the basis of TD-DFT calculations of these model chains, the excitation transitions in the UV spectrum are assigned as Laporte-allowed π−π transitions from MOs with Cu 3dπ and CN π character to empty MOs with Cu 4p and CN π* character. Transitions between the HOMO (3dz) and ...